1. Field of the invention
The invention concerns support and handling devices for batch heat treatment of mechanical parts such as shafts or like members.
2. Description of the prior art
The most commonly used heat treatment devices are of two types: a first type on which the parts are placed and guided and a second type on which the parts are suspended.
Devices of the first type comprise a basic handling tray including columns on which are mounted a lower grid and an upper grid separated by tubular spacers surrounding the columns, each part being supported by an intermediary support member mounted in one of the housings of the lower grid and guided in its upper part by an intermediary guide member mounted in a similar opening in the upper grid.
Devices of the second type include the same component parts as those of the first type except the lower grid and the intermediary guide members, the intermediary support members being of a special type and mounted in the upper grid.
The major disadvantages of both these types of device are the multiplicity of component parts, the high weight of the device as compared with the weight of the parts treated and its commensurate thermal inertia, the complexity of the handling operations for loading the parts which in practise rules out automatic loading and unloading, and finally the imperfect holding of the parts leading to impacts between parts compromising their quality.
An object of the invention is to eliminate the aforementioned disadvantages, in other words to provide a device which, like the previous devices, secures vertical positioning of the parts to avoid deformation during treatment but which is as light as possible whilst grouping the maximum number of parts to maximize the usable load and the number of parts treated per batch, which favors cooling conditions during quenching through good fluid flow, which is highly resistant to thermal shock and to thrust forces in a pusher type furnace and which, finally, enables parts to be loaded in a way that is easily automated.